Lasers have found many uses since their introduction nearly fifty years ago, from the laser diode-based laser pointers available for under $20 to industrial high-power lasers such as are used in cutting and etching tools. All lasers share a few key characteristics—they employ a laser material and an energy source to pump or excite the laser material such that it generates or amplifies light. Light in this sense must be construed broadly, as modern lasers emit radiation ranging from x-ray to long infrared and microwave frequencies. Similarly, laser materials include a wide spectrum of materials, from solids such as ruby rods and solid state devices, to chemicals and gases.
Lasers typically rely upon exciting atoms or molecules within the laser material to an excited quantum energy state, such that electrons within the atoms jump from lower energy level orbits to higher energy level orbits. This process, known as pumping within the laser art, causes a population inversion within the laser material such that more atoms are in the excited quantum energy state than are in the original quantum energy state. Once the laser material is in a state of population inversion, light of a certain frequency passing through the laser material will be amplified as it passes through the laser material.
A significant characteristic of such lasers is that the light amplification in the laser material is coherent, such that the amplified light signal producecd is very nearly the same as the input light signal. This property enables production of the coherent beams of light commonly associated with lasers when the laser material is coupled with a feedback system such as mirrors to produce oscillation in the laser material. The resulting laser beam typically has a very narrow frequency and is very directional relative to other light sources, making lasers useful for a variety of purposes including surveying, cutting, and for optical data storage such as with Compact Discs or DVDs.
But, oscillating a light beam through a laser material often produces a great deal of heat that can damage the laser material, thereby limiting the power produced by various types of lasers. Scientists and engineers are seeking methods for producing higher power lasers for applications such as industrial tools, scientific research, and defense applications.
A laser having an enhanced ability to dissipate heat is therefore desired.